User Manual, AUX FUNCT PROM Manual

Programming
Chapter 3
346
Figure 3.45
AF4
Reciprocal Function Format After Execution
171615141312111076543210Bit No.
Data Address
Result Address
DE
E = Enable Bit (1 = Function in Progress)
D = Done Bit (1 = Function Complete)
11513
S = Sign Bit (1 = Negative)
S
SER
Operand
Result
ER = Error Bit (Illegal Operand, 1 = Input is 0)
(0)
(0) (0) (0) (0)
00 0
12 4
00 8
06 4
Entry and Display of Input and Result Values
Figure 3.45 shows one method of inserting input values and displaying input
values and results of an AF4 reciprocal function. Although there are several
techniques for accomplishing this, we chose get instructions. The first rung
requests execution of an AF4 reciprocal function. The top branch of the second
rung shows the 6-digit operand while the lower branch shows the 6-digit result.
Figure 3.46
AF4
Reciprocal Function Input and Result Display Rungs
201
124
G
305
G
306
064
G
G
200
000
008
Bit
Storage
Execute Aux
Function
Function Number:
Data Addr:
Result Addr: 305
34
200
Error Message
If you try to find the reciprocal of zero, the error bit (bit 145) is set and the
result reads zero.